Collapsible spike

ABSTRACT

A spike erectable from a collapsed or telescoped condition to a fully extended, locked condition for use with an elongated package which is to be partially implanted in the ground after dropping or launching from an aircraft. The spike includes two tubular stages and a third stage terminating in a conical point, the stages being telescopable one within the other. Spring-loaded plungers are carried by the stages for movement into annular grooves formed in adjacent stages to effect locking engagement therewith, and the stages carry fixed pins to limit the degree of relative extension of the stages.

United States Patent [72] Inventor Edgar A. Reed In Elkins Park, Pa. [21] Appl. No. 859,418 [22] Filed Sept. 19, 1969 [45] Patented Aug. 31, 1971 73 Assignee The United States of America as represented by the Secretary of the Navy [54] COLLAPSIBLE SPIKE 4 Claims, 6 Drawing Figs.

[52] 11.8. CI 248/156, 248/159 [51 Int. Cl A45f 3/44 [50] Field of Search 248/156, 408, 159,188.5

[56] References Cited UNITED STATES PATENTS 632,064 8/1899 Roberts 248/1 88.5 248/188.5

2,771,261 11/1956 Niggeloh 3,225,734 12/1965 Bule 248/156 3,318,560 5/1967 Garrette 248/156 FOREIGN PATENTS 717,865 10/1931 France 248/l88.5

Primary ExaminerEdward C. Allen Attorneys-R 5. Sciascia, Henry Hansen and B. Frederick Buchan, Jr.

ABSTRACT: A spike erectable from a collapsed or telescoped condition to a fully extended, locked condition for use with an elongated package which is to be ,partially implanted in the ground after dropping or launching from an aircraft. The spike includes two tubular stages and a third stage terminating in a conical point, the stages being telescopable one within the other. Spring-loaded plungers are carried by the stages for movement into annular grooves formed in adjacent stages to effect locking engagement therewith, and the stages carry fixed pins to limit the degree of relative extension of the stages.

A m 4a 5 31 COLLAPSIBLE SPIKE STATEMENT OF GOVERNMENT INTEREST The invention described herein may-be manufactured and used by or for the Government of the United Statesof America for governmental purposes without the payment of any royalties thereon or therefor;

BACKGROUND OF THE INVENTION This invention generally relates to telescoping members and, more particularly, to a multistage spike erectable from a collapsed or telescoped condition to a locked, extended position.

A need has arisen for a gear delivering package which is suitable for dropping or launching from an aircraft and which assumes, upon impact, a partially buried, implanted position. One mode of delivery contemplates that the package be dropped or launched from an aircraft, forced into a ballistic trajectory by a drogue-type parachute and partially implanted or impaled on the ground. Impact upon landing can subject the package to a deceleration in the range of 600 Gs when launched from high altitudes. Since soil consistency in different areas may range from very hard to very soft, it is necessary that the end of the package to be impaled be equipped with a spike which is configured to assure penetration into hard soil and which is long enough so that the package will not be completely buried upon impact into very soft soil. It is an additional requirement that the spike-tipped package be configured for launching from conventional cylindrical storelaunching apparatus carried by aircraft such as flare-launching apparatus. Accordingly, the total length of packages for launch having sufficiently long noses or spikes must not exceed that permissible in conventional launchers.

SUMMARY OF THE INVENTION It is the general purpose of this invention to provide a collapsible spike which is erectable from a collapsed to a locked, extended position and, more particularly, one which can remain in extended position even under severe loading occasioned by impact with the ground after launch from an aircraft. Still further, it is an object of the invention to provide a spike for air-launchable packages which can be launched by conventional cylindrical store-launching apparatus carried by aircraft.

Briefly, the general purpose and objects of the invention are accomplished by providing a multistage spike having an outermost stage terminating in a point for penetrating the ground, which stage is slidingly receivable withinan adjacent tubular stage and has locking means operable to maintain the stages in extended position even during impact. The invention comprehends the inclusion of spring-loaded plungers carried by one stage and movable into an annular groove formed in the adjacent stage for maintaining the stages in locked, extended positions. Still further the invention contemplates the incorporation of fixed pins carried by one of the stages and slidable along grooves formed in the other of the stages for restraining extension of the stages beyond a position wherein the springloaded plungers are free to move to locking position. Still more particularly, the invention contemplates a triple-stage spike which is of a simple, inexpensive, easily constructed configuration and has a conically pointed end piece telescopable within a pair of sleeves, in turn, telescopable within the other, the spike being erectable to a locked position wherein it can withstand the severe impact occasioned by implantation in ground of varying soil consistencies after launching from an aircrafi.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 represents an end view of a collapsible spike according to the invention in telescoped condition;

FIG. 2 represents an end view of the spike of FIG. 1 arranged in an extended position;

FIG. 3 represents a longitudinal crossfsectional view of the telescoped spike taken generally in cross section along lines 3-3 of FIG. 1;

FIG. 4 represents a longitudinal view of the extended spike taken in cross section generally along lines of 44 of FIG. 2; and

FIGS. 5 and 6 represent cross-sectional views taken perpendicular to the nose axis generally along lines 5-5 and 6-6, respectively, of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2, the spike, generally designated 10, includes nested or telescoped one within the other first and second stages which comprise tubular members 11 and 12 and a third stage comprising a nose or piercing member 13 of generally a circular cross-sectional configuration which terminates in conical point 14 shown in FIGS. 3 and 4 which is adapted for penetrating or impaling the ground. As more particularly shown in FIGS. 3 and4, the first tubular member 11 is of circular, cross-sectional configuration sized to slidingly receive therewithin the second tubular member 12 .also of circular cross-sectional configuration and is attached by a threaded fitting or boss 15 protruding from one end thereof to one end of a package 16 (only partially shown) of generally elongated, cylindrical configuration of similar diameter and suitable for launch or drop from an aircraft.

The tubular member 11 has an annular groove 21 circumscribed about its interior lateral periphery adjacent the other end which is beveled. Four symmetrically arranged key bores 22 extend through the lateral periphery of the tubular member 11 between the annular groove 21 and the exterior lateral periphery of the tubular member 11. A pair of fixed pins, one of which 23 is shown in FIG. 3, are force fit through bores 24 to protrude into the interior of the tube 11 outwardly of the groove 21 in diametrically opposed locations each located equidistant from and between a respective pair of adjacent bores 22.

The second tubular member 12 is slidingly received within the first member 11 and includes at its innermost end an inwardly projecting, integrally formed, plunger-carrying annular flange 31. Four symmetrically arranged plunger bores 32 shown in FIG. 6 radially extend into the flanged end of the tubular member 12 each of which communicates with the interior lateral periphery of the flange 31 through smaller coaxial bores 33. Four locking plungers 34 are normally urged outwardly of the bores 32 by respective springs 35 entrapped in bores 32 so as to bear against the interior lateral periphery of the tubular member 11. When the tubular member 12 is urged outwardly of the tubular member 11 as by gravity or inertia to register the plungers 34 with the bores 22 and the groove 21, the plungers 34 are urged by the springs 35 into the groove 21 to form an interlocking engagement with the tubular member 11, maintaining the relatively extended configuration of the first and second stages. The plungers 34 may be urged into withdrawn positions in the bores 32 by respective keys inserted through the bores 22, thereby permitting the stage 12 to slide to the telescoped position within the member 11 as shown in FIG. 3. The tubular member 32 further has a pair of longitudinally extending, diametrically opposed grooves 36 shown in FIGS. 3 and 5 formed in the exterior lateral periphery thereof terminating in a stop 37 inwardly of the flanged end of the member 12 for slidingly receiving the protruding ends of the fixed pins 23 to limit the extension of the member I2 and center the plungers 34 relative to the groove 21, permitting locking of the members 11 and 12 in relatively extended positions. Like the member 11, tubular member 12 has an annular groove 21 circumscribing its interior lateral periphery adjacent its outermost or unflanged, beveled end which communicates with its exterior lateral periphery through four symmetrically arranged key bores 39. A pair of longitudinally extending, diametrically opposed grooves 40 are formed in the interior lateral periphery of the tubular member 12 and extend from the innermost side of the annular groove 38 toward the flange 311. The pairs of grooves 36 and 40 lie generally in respective mutually perpendicular, axially extending planes symmetrically arranged between the plungers 34 as shown in H6. 5.

The third stage or ground piercing member 13 of the spike is slidingiy receivable in withdrawn or collapsed position completely within the interior of the tubular member 12 as shown in H6. 3 and has a generally cylindrical portion 41 terminating in the conical ground piercing or impaling point 14. A weight reducing, cylindrical cavity 42 extends into the cylindrical portion 41 and communicates with the inclined conical exterior surface of the point M through four symmetrical arranged, forwardly inclined bores 43. The innermost end of the cylindrical portion 4H, like the flanged end ill of the member 12 has formed therein four symmetrically arranged plunger bores 44 extending radially thereinto from the lateral periphery thereof which communicate with the cavity 42 through smaller coaxial bores 45 and are sized to slidingly receive respective ones of four plungers 46 normally urged radially outwardly of the portion 411 by respective springs 47 entrapped therein. A pair of stop pins such as 43 shown in FIG. 4 are force fitted into diametrically opposed bores 49 extending radially into the portion 4i and communicating with the cavity 42 through smaller, coaxial bores 50. The pins 48 are sized to slide along the grooves 40 and are so located adjacent the innermost end of the member 13 so that abutment of their protruding ends with the outermost edge of the annular groove 38 limits the extension of the member 13 relative to the member 12, and centers the plungers 46 carried by member 13 relative to the groove 38 formed in the member 12. A pair of bores 51 shown in FIG. 4 extend radially through the lateral periphery of the member 12; to communicate with the groove 40 adjacent the flange 3]! and are sized to permit insertion of the pins 48 into the bores 49 when the stage 14 has been collapsed or telescoped into the stage 12.

The members l1, l2 and 13 conveniently may all be fabricated from impact extruded or cast aluminum, and the plungers 34 and 46 and pins 23 and 48 are preferably made of heat-treated, corrosion-resistant steel. A convenient way to assemble the spike 10 is to stand the member E2 on its flanged end for receiving the cylindrical portion 41 of the member 13. The plungers 46 are radially compressed into the bores 44 against the action of the springs 47 so that the member 13 drops into telescoped position within member 12 as shown in FIG. 3. Keys are inserted through the bores 39 to force withdrawal of the plungers 46 from the groove 38 and into the bores 44 enabling the cylindrical portion 41 to slide down and seat against the flange 31. The pins 48 are inserted through the bores 51 and force fit into the bores 49 of member 13, protruding therefrom a sufficient degree to prevent withdrawal of the member 13 from member 12 and permit reciprocation of the member 13 to extended position. Thereafter, the springs 35 and the plungers 34 are radially compressed into member 12 to enable telescoping the member 12 into member lll as shown in FIG. 3, using keys inserted through the bores 22 as necessary to prevent locking engagement of the plungers. i

it has been found convenient to use a circular plastic disc having a diameter similar to the exterior diameters of the member 11 or package 16 to interface the package 16 and its collapsed spike 10 with a launcher thereby preventing the inadvertent extension of the spike 30 from its telescoped condition while in the launcher. After launch the spike it) is free to extend to its fully extended, locked position under the action of either gravity or inertia upon the shock of parachute deployment. The pins 23 and 48 prevent extension of the members l2 and 13 beyond the position enabling the springloaded plungers 34 and 46 to lock the spike in extended position. The bores 43 permit the internal flow of air through the members ll, 12 and 13 and prevent the building up of suction which could inhibit the extension of the spike from telescoped condition to fully extended, locked position. Upon impact with the ground some movement of the members 12 and 13 in a collapsing direction is permitted by the plungers 3d and as, thereby absorbing some of the shock of impact, the plungers 34 and 46 being strong enough not to fail. The erected spike 10 is sufficiently long to prevent complete burial of the package 16 having the desired length. The invention, therefore, provides a collapsible spike it which does not collapse under the severe shock incident to impact from an air launch and which can be telescoped to a configuration permitting launch of the package 16 from conventional cylindrical store launching apparatus such as flare launchers carried by aircraft.

Obviously many modifications and variations of the present invention are possible in view of the above teachings. it is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. A spike comprising:

a tubular member having an annular groove circumscribed about the interior lateral periphery thereof and a plurality of grooves longitudinally extending along said periphery;

a piercing member having a cylindrical portion terminating in a conical end formed for soil impalernent, having an opposite end slidably received within said tubular member and being movable from a telescoped position to an extended position, and having ducting formed therethrough extending from the exterior of said conical end to said opposite end received within said tubular member, and a plurality of plunger bores formed therein radially extending into said cylindrical portion; plurality of plungers each received in a respective said plunger bore;

a plurality of springs interposed in said plunger bores to urge said plungers to partially protrude from said cylindrical portion of said piercing member, said plungers being received in locking position by said annular groove when said members are in said extended configuration; and

a plurality of first stop pins protruding from said piercing member slidably received in said longitudinal grooves and being positioned to engage the outmost edge of said annular groove when said plungers are registered with said annular groove, said longitudinal grooves being sufficiently long to enable said piercing member to move to said telescoped position entirely within said tubular member.

2. A spike according to claim 1 further comprising:

said first tubular member including fixed to the other end thereof an inwardly projecting annular flange;

a plurality of spring-loaded plungers carried by said flange and being movable radially from withdrawn to locking position; and

a second tubular member sized to slidingly receive said first tubular member in telescoped position therewithin and having an annular groove circumscribed about the interior lateral periphery thereof adjacent one end for receiving protruding portions of said plungers in said locking position when said first and second tubular members are in an extended configuration.

3. A spike according to claim 2 further comprising:

a second stop pin carried in fixed relation by said second tubular member adjacent said annular groove; and

said first tubular member having a longitudinally extending groove formed in the exterior lateral periphery thereof for slidably receiving said step pin, said longitudinally extending groove terminating in a stop for engaging said stop pin when said plungers of said first tubular member are centered relative said annular groove of said second tubular member.

4. A spike according to claim 3 further comprising:

said first and second tubular members having a plurality of key bores extending through their lateral peripheries, each said key bore being in registry with a respective said plunger when arranged in said locking position and being smaller in diameter than said plunger;

throughits lateral periphery adjacent said flange in registry with a respective said interior longitudinally extending groove, said additional bores being sized to receive 'therethrough said first stop pins. 

1. A spike comprising: a tubular member having an annular groove circumscribed about the interior lateral periphery thereof and a plurality of grooves longitudinally extending along said periphery; a piercing member having a cylindrical portion terminating in a conical end formed for soil impalement, having an opposite end slidably received within said tubular member and being movable from a telescoped position to an extended position, and having ducting formed therethrough extending from the exterior of said conical end to said opposite end received within said tubular member, and a plurality of plunger bores formed therein radially extending into said cylindrical portion; a plurality of plungers each received in a respective said plunger bore; a plurality of springs interposed in said plunger bores to urge said plungers to partially protrude from said cylindrical portion of said piercing member, said plungers being received in locking position by said annular groove when said members are in said extended configuration; and a plurality of first stop pins protruding from said piercing member slidably received in said longitudinal grooves and being positioned to engage the outmost edge of said annular groove when said plungers are registered with said annular groove, said longitudinal grooves being sufficiently long to enable said piercing member to move to said telescoped position entirely within said tubular member.
 2. A spike according to claim 1 further comprising: said first tubular member including fixed to the other end thereof an inwardly projecting annular flange; a plurality of spring-loaded plungers carried by said flange and being movable radially from withdrawn to locking position; and A second tubular member sized to slidingly receive said first tubular member in telescoped position therewithin and having an annular groove circumscribed about the interior lateral periphery thereof adjacent one end for receiving protruding portions of said plungers in said locking position when said first and second tubular members are in an extended configuration.
 3. A spike according to claim 2 further comprising: a second stop pin carried in fixed relation by said second tubular member adjacent said annular groove; and said first tubular member having a longitudinally extending groove formed in the exterior lateral periphery thereof for slidably receiving said stop pin, said longitudinally extending groove terminating in a stop for engaging said stop pin when said plungers of said first tubular member are centered relative said annular groove of said second tubular member.
 4. A spike according to claim 3 further comprising: said first and second tubular members having a plurality of key bores extending through their lateral peripheries, each said key bore being in registry with a respective said plunger when arranged in said locking position and being smaller in diameter than said plunger; said piercing member having bores for receiving and holding in fixed relation ends of respective ones of said first stop pins; and said first tubular member having additional bores extending through its lateral periphery adjacent said flange in registry with a respective said interior longitudinally extending groove, said additional bores being sized to receive therethrough said first stop pins. 